The Affect of Application Volume and Deposition Aids on Droplet Spectrum and Deposition for Aerial Applications

Presented at ASAE/NAAA Technical Session38th Annual NAAA Convention

Silver Legacy Hotel and CasinoDec. 6, 2004

Robert E. Wolf

Paper # AA04-006Biological and Agricultural Engineering

Objective:

The objective of this study was to evaluate the affect of deposition aids and application volume on droplet spectrum and canopy penetration for a fixed wing aerial application.

Materials and Methods: Soybean circle, Ingalls, KS August 30, 2004 (8:00-10:00 AM) Design 2 x 5 (10 treatments with 3 reps

each) Products completely randomized All treatments parallel to the wind Soybeans were 36-46 inches tall

• R6 growth stage and 90% canopy fill Application Conditions:

• 58-70°F temperature• 77% average relative humidity• Wind speed:

Range = 5-11 mph Average = 8.8 mph Direction range = 170 - 210 degrees

Materials and Methods:

AT 401W (Ingalls Aerial)

• Walters Engine Conversion• Drop booms• CP-09 nozzles w/30° deflection• 3 GPA (35 nozzles)

2/3 - .078 and 1/3 - .125

• 1 GPA (33 nozzles) .062 • 29 psi• Average speed 129 mph GPS measured• Medium droplets – USDA Worksheets

Aircraft Operation S.A.F.E. calibrated Application Height 10-12 feet

Materials and Methods:

4 deposition aids:• Preference• Preference + Placement• Interlock + Preference• Interlock + Rivet

Water used as a check Spray mixes containing 50 gal

• NIS (Crop Oil Concentrate) @ 3 ounces/acre

• Tap water• Required amount of product or

combination of products per label

Application volumes• 3 GPA• 1 GPA

Collection Procedure for canopy:

1 pass7 collectors evenly

spaced across the swath width

3 kromekote papers on each collector

placed in top, middle, and bottom of canopy = 21 papers

4 papers in non canopy area

DropletScan used to analyze droplets:

System ComponentsSystem Components

Analysis Procedure:

Scanned and recorded• 630 canopy papers (7 x 3 x 10

x 3)• 120 outside canopy (4 x 10 x

3)• VMD and % Area Coverage

Statistical analysis with SAS• Proc GLM• LS Means compared

Alpha = .10

Results and Discussion:

Comparison of locations in canopyComparison of application volumeAssessment of Droplet SpectraComparison of products

LS Means and rank: (percent area coverage all positions)

Treatment1 Top2 Rank Middle Rank Bottom Rank No Canopy

Rank VMD Rank

1 1.17a 5 0.23b Tie 8 0.10b

Tie 6 2.80a 4 300a

5

2 0.63d 10 0.23b Tie 8 0.07b

10 1.76b 10 293a

7

3 1.17a 4 0.30a 5 0.23a

Tie 3 5.07a 1 334a

1

4 0.77c Tie 7 0.20c 10 0.10b

Tie 6 2.40a 8 254b

10

5 0.87b 6 0.27a Tie 6 0.10b Tie 6 2.50a 7 300a 4

6 0.77c Tie 7 0.63a 1 0.60a

1 2.53a 6 282a

8

7 2.00a 1 0.53a 3 0.37a

2 4.60a 2 327a

2

8 0.77c Tie 7 0.33a 4 0.10b

Tie 6 1.83b 9 299a

6

9 1.67a 2 0.60a

2 0.23a Tie 3 2.70a

5 279a 9

10 1.57a 3 0.27a Tie 6 0.17a 5 3.33a 3 311a 3

Average 1.14 0.36 0.21 2.95 298

Red circle represents 3 GPA treatments1See table 1 for description of products used in each treatment.2Means with the same letter are not significantly different.

Percent area coverage all positions:

0.00

0.50

1.00

1.50

2.00

2.50

1 2 3 4 5 6 7 8 9 10

Treatments

% a

rea

co

ve

rag

e

top middle bottom

1 & 2 = Water 3 & 4 = Preference 5 & 6 = Placement/Preference

7 & 8 = Interlock/Preference 9 & 10 = Interlock/Rivet

Average Coverage All Positions:

2.95

0.36 0.21

1.14

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

no canopy top middle bottom

Canopy Positions

Pe

rce

nt

Are

a C

ov

era

ge

VMD for No Canopy Collections:

0

50

100

150

200

250

300

350

400

1 2 3 4 5 6 7 8 9 10

Treatments

VM

D

1 & 2 = Water 3 & 4 = Preference 5 & 6 = Placement/Preference

7 & 8 = Interlock/Preference 9 & 10 = Interlock/Rivet

Average Coverage Across Canopy Position at 3 GPA*

0.570.41

0.97

0.83

0.5

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Water Preference(COC)

Placement +Preference

Inerlock +Preference

Inerlock +Rivet

Treatments

Per

cent

Are

a C

over

age

*sum of top, middle, and bottom averaged

Summary of findings:

Top of canopy had highest coverage.Canopy reduced coverage by 3 times.3 GPA had more canopy coverage than 1 GPA.Droplet spectra slightly influenced - larger. Deposition aids increased canopy penetration.Product differences were measured.Highest coverage - Interlock and Preference.

Acknowledgements:• Agriliance• Ingalls Aerial• Tom Miller• Brian Oyler

Field Test Comparisons of Drift Reducing Products for Fixed Wing Aerial Applications Robert E. Wolf, Kansas State University, Manhattan, Kansas

Dennis R. Gardisser, University of Arkansas, Little Rock, Arkansas

AbstractTwenty-one drift control products were compared for reducing horizontal and vertical drift for fixed wing aerial applications. Water-sensitive paper and DropletScan™ software was used to collect and compare the differences in drift.

A low-score performance value at the low wind profile (6.8 Km/h) was used to rank each products ability to reduce drift.

A few of the products exhibited less drift potential than water alone. Several of the products exhibited the same or more drift potential than water alone.

Products C and P had the lowest amount of horizontal drift with the Air Tractor with H being the lowest for the Cessna.

In the vertical profile product C and T had the least drift for the Air Tractor and L had the least drift for the Cessna.

Equipment and Products AT 502A

• Drop booms• CP-09 nozzles w/5° deflection• Combination of .078 and .125 orifice settings• 276 kPa (40 psi)• 241 km/h (150 mph ground speed by radar)

Cessna 188 Ag Husky• Ag Tips• CP-03 w/30 degree deflection• Combination of .078 and .125 orifice settings• 179 kPa (26 psi)• 185 km/h (115 mph ground speed by radar)

Aircraft calibrated for 28 L/ha (3 GPA)

Vertical collectors on drif t tower

Horizontal collectors

Flight line

Wind direction

Weather Station

[H15 to H 107m]

[214 m

eters]

[0 to 12m]

Conclusions:Differences in products are shown at all horizontal and vertical

collector positions.

Products A, Q, G, F, D, R, O, and K all tallied higher performance scores than water for the Air Tractor on the horizontal collectors. Products A, R, Q, O, J, I, L, G, M, B, N and K were higher for the Cessna.

For the vertical profile, products K, D, Q, R, and O and products I, B, J, C, and K were higher than water for the Air Tractor and Cessna respectively.

Products C and P had the lowest amount of horizontal drift with the Air Tractor with H being the lowest for the Cessna.

In the vertical profile product C and T had the least drift for the Air Tractor and L had the least drift for the Cessna.

ObjectiveThis study evaluated the influence of selected drift control products/deposition aids on horizontal and vertical spray drift during two selected fixed wing aerial application scenarios.

IntroductionOff-target drift is a major source of application inefficiency. Application of crop protection products with aerial application equipment is a complex process. In addition to meteorological factors, many other conditions and components of the application process may influence off-target deposition of the applied products. Spray formulations have been found to affect drift from aerial applications. Materials added to aerial spray tank mixes that alter the physical properties of the spray mixture affect the droplet size spectrum. With new nozzle configurations and higher pressure recommendations, and with the continued development of drift reducing tank mix materials, applicators seek to better facilitate making sound decisions regarding the addition of drift control products into their tank mixes.

Results: Low-Score Performance RankA low-score performance value was tabulated for each product at

all horizontal and vertical collector postitions for each airplane.

Score was based on lowest drift amount at the low wind profile.

Drift Collector

Table 2. Final rank of each product for horizontal drift.

Table 3. Final rank for each product for vertical drift.

Figure 1. Cessna 188 Ag Huskey.

Figure 2. Air Tractor 502A. Figure 3. Horizontal collector with

water-sensitive paper.

Figure 4. Vertical collection tower.

Table 1. Product codes, companies, and mixing rates.